To clarify the effects of working inside and outside the cold storage warehouse on health of workers operating a forklift at a cold storage facility, A time-motion study was conducted and the change in the circulatory function was monitored with male workers in a preliminary survey. Based on its results, an experimental study was made in winter and in summer with male subjects occupationally unexposed to cold environments. Furthermore, the time-motion study was conducted and the changes in the circulatory and the psychological functions were monitored with male workers operating a forklift at a cold storage facility in a survey. We examined the relationship between working or insulated conditions and the changes in the circulatory or the psychological functions. The results are as follows :In the preliminary survey, the blood pressure was increased during the work inside and outside the cold storage warehouse. The increasing total time of staying in the cold storage warehouse lead to t
… Morehe increasing adrenaline and noradrenaline concentrations in blood, and the decreasing sublingual temperature. The increasing noradrenaline concentration in blood lead to the increasing blood pressure.In the experimental study, the systolic blood pressure and the noradrenaline concentration in blood were increased with increasing time of staying in the cold storage warehouse or decreasing clothing insulation. The decreased sublingual temperature was significantly larger as the time of staying in the cold storage warehouse was longer. These trends were more outstanding in winter than in summer. The Kraepelin test as the psychological function was not affected by the time of staying in the cold storage warehouse.In the survey, the mean total frequency of entering the cold storage warehouse in a day was 58 times in winter and 64 times in summer. It showed a large individual difference. The mean total time of staying in the cold storage warehouse was 4 hours and 33 minutes in winter and 7 hours and 4 minutes in summer. The symptom "coldness or pain in hands or legs" was complained with more than 60 - percent of workers both in winter and in summer. The blood pressure showed no difference between measured inside and outside the cold storage warehouse. The systolic blood pressure was higher in winter than in summer. The catecholamine concentrations in blood had the tendency to increase at the end of work than at the start of work. Their differences in summer were significant. The baseline concentrations were higher in winter than in summer. The sublingual temperature decreased at the end of work and its change was associated with the total time of staying in the cold storage warehouse. There was no clear relationship bet ween the total frequency of entering the cold storage warehouse and the change in the blood pressure or the catecholamine concentrations in blood.In summary, the work inside and outside the cold storage warehouse has effects on the circulatory functions, such as increasing blood pressure and catecholamine concentrations in blood and decreasing sublingual temperature. The effects are larger as total time in staying in the cold storage warehouse is longer. The effects are larger in winter than in summer. This may result from not the health effect of the difference in the environmental temperature, but longer exposure time to the cold environments in winter. There is a possible effect on the psychological function estimated by Kraepelin test.To establish the suitable working conditions for workers operating a forklift at the cold staorage facility, the circulatory and the psychological functions, as health effects of exposure to cold environments, should be considered as well as metabolism activated by the exposure to cold environments. The examination of the clothing insulation and progress of work administration are made with considering the effects on the circulatory or the psychological functions as well as health administration. Less